Limit the type for kubectl expose command

docs/man/man1/kubectl-expose.1

@@ -3,7 +3,7 @@
 
 .SH NAME
 .PP
-kubectl expose \- Take a replicated application and expose it as Kubernetes Service
+kubectl expose \- Take a replication controller, service or pod and expose it as a new Kubernetes Service
 
 
 .SH SYNOPSIS
@@ -13,10 +13,10 @@ kubectl expose \- Take a replicated application and expose it as Kubernetes Serv
 
 .SH DESCRIPTION
 .PP
-Take a replicated application and expose it as Kubernetes Service.
+Take a replication controller, service or pod and expose it as a new Kubernetes Service.
 
 .PP
-Looks up a replication controller or service by name and uses the selector for that resource as the
+Looks up a replication controller, service or pod by name and uses the selector for that resource as the
 selector for a new Service on the specified port. If no labels are specified, the new service will
 re\-use the labels from the resource it exposes.
 
@@ -219,6 +219,9 @@ $ kubectl expose rc nginx \-\-port=80 \-\-target\-port=8000
 # Create a service for a replication controller identified by type and name specified in "nginx\-controller.yaml", which serves on port 80 and connects to the containers on port 8000.
 $ kubectl expose \-f nginx\-controller.yaml \-\-port=80 \-\-target\-port=8000
 
+# Create a service for a pod valid\-pod, which serves on port 444 with the name "frontend"
+$ kubectl expose pod valid\-pod \-\-port=444 \-\-name=frontend
+
 # Create a second service based on the above service, exposing the container port 8443 as port 443 with the name "nginx\-https"
 $ kubectl expose service nginx \-\-port=443 \-\-target\-port=8443 \-\-name=nginx\-https
 

docs/user-guide/kubectl/kubectl.md

@@ -85,7 +85,7 @@ kubectl
 * [kubectl delete](kubectl_delete.md)	 - Delete resources by filenames, stdin, resources and names, or by resources and label selector.
 * [kubectl describe](kubectl_describe.md)	 - Show details of a specific resource or group of resources
 * [kubectl exec](kubectl_exec.md)	 - Execute a command in a container.
-* [kubectl expose](kubectl_expose.md)	 - Take a replicated application and expose it as Kubernetes Service
+* [kubectl expose](kubectl_expose.md)	 - Take a replication controller, service or pod and expose it as a new Kubernetes Service
 * [kubectl get](kubectl_get.md)	 - Display one or many resources
 * [kubectl label](kubectl_label.md)	 - Update the labels on a resource
 * [kubectl logs](kubectl_logs.md)	 - Print the logs for a container in a pod.
@@ -100,7 +100,7 @@ kubectl
 * [kubectl stop](kubectl_stop.md)	 - Deprecated: Gracefully shut down a resource by name or filename.
 * [kubectl version](kubectl_version.md)	 - Print the client and server version information.
 
-###### Auto generated by spf13/cobra at 2015-09-10 18:53:03.165115265 +0000 UTC
+###### Auto generated by spf13/cobra at 2015-09-11 06:17:55.670147499 +0000 UTC
 
 <!-- BEGIN MUNGE: GENERATED_ANALYTICS -->
 [![Analytics](https://kubernetes-site.appspot.com/UA-36037335-10/GitHub/docs/user-guide/kubectl/kubectl.md?pixel)]()

docs/user-guide/kubectl/kubectl_expose.md

@@ -33,14 +33,14 @@ Documentation for other releases can be found at
 
 ## kubectl expose
 
-Take a replicated application and expose it as Kubernetes Service
+Take a replication controller, service or pod and expose it as a new Kubernetes Service
 
 ### Synopsis
 
 
-Take a replicated application and expose it as Kubernetes Service.
+Take a replication controller, service or pod and expose it as a new Kubernetes Service.
 
-Looks up a replication controller or service by name and uses the selector for that resource as the
+Looks up a replication controller, service or pod by name and uses the selector for that resource as the
 selector for a new Service on the specified port. If no labels are specified, the new service will
 re-use the labels from the resource it exposes.
 
@@ -57,6 +57,9 @@ $ kubectl expose rc nginx --port=80 --target-port=8000
 # Create a service for a replication controller identified by type and name specified in "nginx-controller.yaml", which serves on port 80 and connects to the containers on port 8000.
 $ kubectl expose -f nginx-controller.yaml --port=80 --target-port=8000
 
+# Create a service for a pod valid-pod, which serves on port 444 with the name "frontend"
+$ kubectl expose pod valid-pod --port=444 --name=frontend
+
 # Create a second service based on the above service, exposing the container port 8443 as port 443 with the name "nginx-https"
 $ kubectl expose service nginx --port=443 --target-port=8443 --name=nginx-https
 
@@ -122,7 +125,7 @@ $ kubectl expose rc streamer --port=4100 --protocol=udp --name=video-stream
 
 * [kubectl](kubectl.md)	 - kubectl controls the Kubernetes cluster manager
 
-###### Auto generated by spf13/cobra at 2015-09-11 03:36:48.458259032 +0000 UTC
+###### Auto generated by spf13/cobra at 2015-09-14 01:48:52.452547937 +0000 UTC
 
 <!-- BEGIN MUNGE: GENERATED_ANALYTICS -->
 [![Analytics](https://kubernetes-site.appspot.com/UA-36037335-10/GitHub/docs/user-guide/kubectl/kubectl_expose.md?pixel)]()

hack/lib/test.sh

@@ -132,3 +132,21 @@ kube::test::describe_resource_assert() {
   echo -n ${reset}
   return 0
 }
+
+kube::test::if_has_string() {
+  local message=$1
+  local match=$2
+
+  if [[ $(echo "$message" | grep "$match") ]]; then
+    echo "Successful"
+    echo "message:$message"
+    echo "has:$match"
+    return 0
+  else
+    echo "FAIL!"
+    echo "message:$message"
+    echo "has not:$match"
+    caller
+    return 1
+  fi
+}

hack/test-cmd.sh

@@ -680,6 +680,13 @@ __EOF__
   kubectl delete pod valid-pod "${kube_flags[@]}"
   kubectl delete service frontend{,-2,-3,-4,-5} "${kube_flags[@]}"
 
+  ### Expose negative invalid resource test
+  # Pre-condition: don't need
+  # Command
+  output_message=$(! kubectl expose nodes 127.0.0.1 2>&1 "${kube_flags[@]}")
+  # Post-condition: the error message has "invalid resource" string
+  kube::test::if_has_string "${output_message}" 'invalid resource'
+
   ### Delete replication controller with id
   # Pre-condition: frontend replication controller is running
   kube::test::get_object_assert rc "{{range.items}}{{$id_field}}:{{end}}" 'frontend:'

pkg/kubectl/cmd/cmd_test.go

@@ -227,15 +227,19 @@ func NewAPIFactory() (*cmdutil.Factory, *testFactory, runtime.Codec) {
 		ClientConfig: func() (*client.Config, error) {
 			return t.ClientConfig, t.Err
 		},
+		CanBeExposed: func(kind string) error {
+			if kind != "ReplicationController" && kind != "Service" && kind != "Pod" {
+				return fmt.Errorf("invalid resource provided: %v, only a replication controller, service or pod is accepted", kind)
+			}
+			return nil
+		},
 		Generator: func(name string) (kubectl.Generator, bool) {
 			generator, ok := generators[name]
 			return generator, ok
 		},
 	}
-
 	rf := cmdutil.NewFactory(nil)
 	f.PodSelectorForObject = rf.PodSelectorForObject
-
 	return f, t, testapi.Default.Codec()
 }
 

pkg/kubectl/cmd/expose.go

@@ -34,9 +34,9 @@ type ExposeOptions struct {
 }
 
 const (
-	expose_long = `Take a replicated application and expose it as Kubernetes Service.
+	expose_long = `Take a replication controller, service or pod and expose it as a new Kubernetes Service.
 
-Looks up a replication controller or service by name and uses the selector for that resource as the
+Looks up a replication controller, service or pod by name and uses the selector for that resource as the
 selector for a new Service on the specified port. If no labels are specified, the new service will
 re-use the labels from the resource it exposes.`
 
@@ -46,6 +46,9 @@ $ kubectl expose rc nginx --port=80 --target-port=8000
 # Create a service for a replication controller identified by type and name specified in "nginx-controller.yaml", which serves on port 80 and connects to the containers on port 8000.
 $ kubectl expose -f nginx-controller.yaml --port=80 --target-port=8000
 
+# Create a service for a pod valid-pod, which serves on port 444 with the name "frontend"
+$ kubectl expose pod valid-pod --port=444 --name=frontend
+
 # Create a second service based on the above service, exposing the container port 8443 as port 443 with the name "nginx-https"
 $ kubectl expose service nginx --port=443 --target-port=8443 --name=nginx-https
 
@@ -58,7 +61,7 @@ func NewCmdExposeService(f *cmdutil.Factory, out io.Writer) *cobra.Command {
 
 	cmd := &cobra.Command{
 		Use:     "expose (-f FILENAME | TYPE NAME) [--port=port] [--protocol=TCP|UDP] [--target-port=number-or-name] [--name=name] [----external-ip=external-ip-of-service] [--type=type]",
-		Short:   "Take a replicated application and expose it as Kubernetes Service",
+		Short:   "Take a replication controller, service or pod and expose it as a new Kubernetes Service",
 		Long:    expose_long,
 		Example: expose_example,
 		Run: func(cmd *cobra.Command, args []string) {
@@ -113,7 +116,9 @@ func RunExpose(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []str
 	}
 	info := infos[0]
 	mapping := info.ResourceMapping()
-
+	if err := f.CanBeExposed(mapping.Kind); err != nil {
+		return err
+	}
 	// Get the input object
 	inputObject, err := r.Object()
 	if err != nil {

pkg/kubectl/cmd/util/factory.go

@@ -86,6 +86,8 @@ type Factory struct {
 	DefaultNamespace func() (string, bool, error)
 	// Returns the generator for the provided generator name
 	Generator func(name string) (kubectl.Generator, bool)
+	// Check whether the kind of resources could be exposed
+	CanBeExposed func(kind string) error
 }
 
 // NewFactory creates a factory with the default Kubernetes resources defined
@@ -246,6 +248,12 @@ func NewFactory(optionalClientConfig clientcmd.ClientConfig) *Factory {
 			generator, ok := generators[name]
 			return generator, ok
 		},
+		CanBeExposed: func(kind string) error {
+			if kind != "ReplicationController" && kind != "Service" && kind != "Pod" {
+				return fmt.Errorf("invalid resource provided: %v, only a replication controller, service or pod is accepted", kind)
+			}
+			return nil
+		},
 	}
 }
 

pkg/kubectl/cmd/util/factory_test.go

@@ -165,6 +165,33 @@ func TestLabelsForObject(t *testing.T) {
 	}
 }
 
+func TestCanBeExposed(t *testing.T) {
+	factory := NewFactory(nil)
+	tests := []struct {
+		kind      string
+		expectErr bool
+	}{
+		{
+			kind:      "ReplicationController",
+			expectErr: false,
+		},
+		{
+			kind:      "Node",
+			expectErr: true,
+		},
+	}
+
+	for _, test := range tests {
+		err := factory.CanBeExposed(test.kind)
+		if test.expectErr && err == nil {
+			t.Error("unexpected non-error")
+		}
+		if !test.expectErr && err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+	}
+}
+
 func TestFlagUnderscoreRenaming(t *testing.T) {
 	factory := NewFactory(nil)